Tubing anchor



Nov. 6, 1956 w. H. MGKisslcK ETAL TUBING ANCHOR 2 Sheets-Sheet Filed April 30, 1951 w.H. lvKlssrcK JE. FATE,JR.

ATTORNEY NOV. 6, l1956 Wi H, McKlSslcK l- TAL 2,769,499

TUBING ANCHOR 2 sheets-sheet 2 Filed April 30, 1951 United Sates Patent O TBIG ANCHOR William H. McKissick and .lessee E. Fate, r., Tulsa, Gkla. Application April 3o, 1951, serial No. 223,759

1 Claim. (Cl. 166-209) This invention relates to improvements in oil well pumping apparatus, and more particularly, but not by way of limitation, to an improved anchor for securing a string of well tubing in the casing of an oil well.

As it is well known, the majority of oil producing wells are pumped by use of a mechanically actuated subsurface pump, usually termed a sucker rod pump. The pump housing is secured to the lower end of a string of well tubing which is in turn disposed in the well casing. The Well tubing is suitably anchored at the surface of rthe well and extends downwardly in the well casing to a position adjacent the producing sands and in communication with the well lluid. A plurality of sucker rods are interconnected in tandem relation and extend downwardly through the well tubing into connection with the plunger of the sucker rod pump. The sucker rods are alternately raised and lowered by suitable surface equipment to actuate the pump plunger, which in turn displaees the well uid upwardly through the well tubing to the surface of the well. It will be apparent that as the pump plunger is moved through the pump housing, a force will be imposed on the well tubing to alternately stretch and compress the tubing, particularly in wells of relatively great depth. When the lower end of the well tubing, and hence the pump housing, is moved simultaneously with the pump plunger, although to a lesser degree, the eiciency of the pump is impaired. Furthermore, the frequent deformation of the well tubing induces fatigue and loss of strength.

The present invention contemplates a novel anchor adapted to be interposed in the well tubing adjacent the lower end thereof and function to secure the lower portion of the tubing to the well casing, thereby precluding stretching or elongation of the tubing string. A plurality of slips are carried by the anchor and are adapted to be automatically actuated into gripping contact with the well casing by the action of a helical spring upon turning the well tubing in one direction. In this manner, the anchor may be set at any predetermined height and without moving the tubing longitudinally to actuate the slips as is usually necessary in this type of device.

An important object of this invention is to provide a novel anchor for securing a string of well tubing in the casing of an oil well.

Another object of this invention is to provide an automatically actuated tubing anchor that may be set at any predetermined position in the Well casing.

Another object of this invention is to increase the efficiency of oil well pumping apparatus, and increase the service life of well tubing utilized with sucker rod pumps.

A further object of this invention is to provide a novel tubing anchor utilizing springs for actuation of the slips thereof.

A still further object of this invention is to provide an eicient tubing anchor wln'ch may be economically manufactured.

Other objects and advantages of the invention will be evident from the following detailed description, read in 2 conjunction with the accompanying drawings which illustrate my invention.

In the drawings:

Figure 1 is an elevational view of a novel tubing anchor disposed in a well casing with a quarter section of the anchor removed for clarity.

Figure 2 is a sectional view taken along lines 2 2 of Fig. l.

Figure 3 is another sectional view taken along lines 3 3 of Fig. l.

Figure 4 Vis a View similar to Fig. l illustrating the tubing anchor in anchoring position.

Figure 5 is a sectional view taken along lines 5 5 of Fig. l.

Figure 6 is still another sectional view taken along lines 6 6 of Fig. l.

Figure 7 is a perspective View of the actuating sleeve of the tubing anchor.

Referring to the drawings in detail and particularly Figure l, reference character S designates a well casing disposed in the bore (not shown) of an oil well. A string of well tubing l@ extends downwardly through the well casing 8 to a position adjacent the producing sands (not shown) in the usual manner. A novel tubing anchor generally indicated at 12 is interposed in the lower portion of the tubing string lil to anchor the tubing lil to the well casing 8 as will be hereinafter set forth.

The tubing anchor 12 comprises a tubular mandrel 14 having a head 16 threadedly secured on the upper end thereof. A cylindrical extension 1S extends upwardly from the head i6 and is threadedly secured to an intermediate portion of the tubing 1Q. As clearly shown in Figure 2, a plurality of circumferentially spaced vertical grooves are provided in the outer periphery of the head 16 to permit substantially free vertical movement of the anchor 12 through the casing 8 when the casing 8 contains well fluid. The head 16 extends downwardly around the tubular mandrel 14 and has three (but not limited thereto) U-shaped brackets 22 extending outwardly from the lower end thereof as is more clearly shown in Figure 3. Each bracket 22 loosely receives a slip 24 having downwardly extending teeth or serrations 26 (Fig. l) on a portion of the outer periphery thereof. A tapered shoulder 2S is provided on the outer surface of each slip member 24 and is adapted to contact the respective bracket 22 to limit the downward movement of the slips 24 and retain the slips 24 in assembly on the mandrel 14. A tapered surface 30 is provided on the head 16 adjacent each of the slips 24 to facilitate the outward movement of the slips 24 when the slips are moved upwardly, as will be hereinafter set forth. A retaining ring 32 is loosely disposed on the mandrel 14 below the brackets 22 to receive the lower ends 34 of the slips 24. The lower end 34 of each slip 24 extends outwardly into a circumferential groove 36 provided in the inner surface of the retaining ring 32 to secure the slips 24 in the retaining ring 32. Y

An actuating sleeve 38 is loosely disposed on the mandrel 14 below the retaining ring 32 and is adapted to actuate Vthe retaining ring 32 and slips 24 as will be more fully hereinafter set forth. An outwardly extending circumferential flange 4t) is provided on the upper end of the sleeve 38 -to assure contact of the sleeve 38 with the retaining ring 32 upon upward movement of the sleeve 33. The walls of the sleeve 38 are cut away as clearly shown in Fig. 7 to provide a pair of curved surfaces 42 of helical configuration adjacent the upper end of the sleeve 38. A sleeve or band 44 is welded or otherwise rigidly secured on the mandrel 14 in a position opposite the helical surfaces 42, as shown in Fig. l. A pair of studs 46 are rigidly secured to the sleeve 44 and extend outwardly therefrom through the sleeve 38 (see also Fig. 5). The studs 46 cooperate with the helical surfaces 42 to alternately actuate and release theactuating sleeve 38 upon rotation of the mandrel 14 as will be hereinafter set forth. A suitable bearing unit 48 is provided on each stud 46 to facilitate the movement of the studs 46 over the surfaces 42. Each helical surface 42 communicates with a semi-circular recess 50 at the upper end thereof to provided a seat forthe respective stud 46 when the sleeve 38 is in a retracted or down position to preclude inadvertent actuation of the sleeve 38, as will be hereinafter'set forth.

Three (but not limited thereto) friction or belly springs 52 are disposed opposite the mandrel 14 below the actuating sleeve 38. The upper end 54 of each friction spring 52 extends into a complementary longitudinal slot S6 in the actuating sleeve 38. As clearly shown in Figure 6, the upper end 54 of each spring 52 is secured to a ring 58 loosely disposed on the tubular mandrel 14 within the actuating sleeve 38. The sleeve 38 may therefore be moved vertically to a limited extent independent of the friction springs 52. However, since the springs 52 extend outwardly into engagement with the well casing 8, the ends 54 thereof will cooperate with the slots 56 to preclude rotation of the actuating sleeve 38. An inwardly projecting flange 60 is provided on the lower end of the sleeve 38 to contact the ring 58 upon upward movement of the actuating sleeve 38 and limit the upward movement thereof.

Another sleeve 62 is loosely disposed on the mandrel 14 in downwardly spaced relation to the actuating sleeve 38. A plurality of vertical slots 64 are provided in the sleeve 62 to receive the lower ends 66 of the friction springs 52. The lower end 66 of each spring 52 is secured to a ring 68 similar in construction to the ring 58 previouslyV described. Vertically spaced flanges 70 extend inwardly from the sleeve 62 to limit the independent movement of the sleeve 62 and the springs 52. The sleeve 62 normally rests on a ycoupling 72 threadedly secured onV the lower end of the tubular mandrel 14.' The well tubing is also Vthreadedly secured to the couplingV 72 and extends downwardly therefrom into connection with the pump housing (not shown).of a sucker rod pump (not shown).

. A helical spring 74 is provided around the mandrel 14 between the actuating sleeve 38 and the sleeve 62. The spring 74 constantly urges the actuating sleeve 38 in an upward direction and is of suicient strength to move the actuating sleeve 38, retaining ring 32 and slips 24 in an upward direction when the actuating sleeve 38 is released by the studs 46 as will be hereinafter set forth. A suitable well packer (not shown) is preferably provided Von the tubing V10 above the tubing anchor 12 in a manner wellV known in the art.

Operation.

Preparatory to inserting the tubing anchor 12 in the well casing 8, the actuating sleeve 38 is placed in the retracted or down position as shown in Figure l with each stud 46 in its respective seat 50. The tubing string 10 with the tubing anchor 12'interposed therein is then lowered through the well casing 8 to position the tubing 10 at the desired height. It will be notedV that the friction springs 52 are constantly in engagement with the well casing 8 to preclude rotation of the actuating sleeve V38. When the tubing anchor 12 is positioned in the well casing 8, the .tubing 1() is turned in a clockwise direction (referring to the surface of the Well) by use of suitable surface equipment (not shown)'to simultaneously turn the mandrel 14. Eachstud 46 is thereby moved out of its respective seat 50 and'through'the respective cut away portion of the sleeve 38 to release the actuating sleeve 38. YThe helical spring 74 then forces the actuating Ysleeve 38 in an upward direction to the position shown in Figure 4. T heupper flanged end 40 of the actuating sleeveV 38 contacts the lower end of the retaining ring 32 during upward movement of the sleeve 38 to simultaneously move the retaining ring 32 and slipsV 24 upwardly to the position shown in Figure 4. The slips 24 are therefore moved upwardly over theV tapered surfaces 30 of the head 16 and are forced outwardly to place the teeth 26 in engagement with the well casing 8. In 6 this position of the tubing anchor 12, the downwardly extending teeth 26 will in effect bite into the inner surface of the well casing 8 and preclude downward movement of the tubing string 10 relative to the well casing 8 during operation of the sucker rod pump.

When itis desired to remove the tubing 10 from the casing 8, the tubing 10 is turned in a'counter-clockwise direction. Each Vroller 48 of'each stud 46 isA therefore forced over the respective helicalsurface 42 to progressively force the actuating sleeve 38 in a downward direc- 1.5 tion against the action of a helical spring 74. The Y tubing 1? is turned in a counter-clockwise direction until the studs 46 are disposed in the seats 50 as shown inV Figure l. The sleeve 38 will thereby be' moved downwardly along the mandrel 14 belowthe retaining ring 32 to relieve the force previously exerted on the retaining ring 32 to retain the slips 24 in engagement with the well casing 8. The tubing 10 is then pulled upwardly in the usual manner, whereupon the slips 24 become disengaged from the well 'casing S and fall by gravity until the 25 tapered surfaces 28 contact the respective brackets 22 as illustrated in Figure l. The brackets 22 cooperate with the retaining ring 32 to retain the slips 24 in assembly on the mandrel 14 during the upward and downward movement thereof. It will be apparent that Vthe vertical slots 56 permit free movement of the actuating sleeve 38 relative to the friction springs 52 during operaf tion of the tubing anchor 12. Y

From the foregoing, it is apparent that the present invention provides a novelV tubing anchor for elfectively securing a string of tubing in a well casing.V The well tubing is merely turned to Yactuate and release the slipY members of the tubing anchor and the tubing may be anchored at any predetermined position relative to the well casing. The actuating springl is of sucientstrength 40 Y to lift the slip members independentof the vertical move-Y ment of the well tubing. Therefore, the well tubing needV not be raised or lowered to set the tubing anchor as is usually required in devices of this character. It is alsoY apparent that the present invention will increase the eciency of sucker rod type pumps and provides an elicien'tV tubing anchor which may be economically manufactured.

Changes may be made in the combination and arrangement of parts as heretofore set'forth in the specificationV and shown in the drawings, it being understood that any modification inthe precise embodiment'of the invention `may be made within the scope of the `following claim without departing from the spirit of our invention.

We claim: Y

A tubing anchor for anchoring a stringof tubing in the casing of an oil well, comprising `a tubular mandrel interposed in the string of tubing, an :actuating sleeve loosely disposed on the mandrel and having slots therein,

a lower sleeve member on the lower vend of the mandrel,

stop means on the mandrel limiting downward Vmovement of the lower sleeve,V a plurality of'friction springs disposed around the mandrel and radially spacedY there-V from in engagement with the well casing, saidv friction springs having one end thereof slidably disposed in the slots of the actuating sleeve in a manner to provide limited longitudinal movement of the sleeve relative to the friction springs, and the opposite end of each friction spring secured to the lower sleeve member, whereby'the friction springs preclude rotation of the actuating sleeve with respect to the well casing when the mandrel is rotated 7G relative to the actuating sleeve, a helical spring around Ythe Ymandrel anchored at its lower end to said lower sleeve member and vcontinually urging the actuating sleeve upwardly over the mandrel, a helical Vslot Vin the'actuat- Ying sleeve, a stud on the mandrel extending into the helical slot and operable to move the actuating sleeve down- Wardly upon rotation of the mandrel in one direction against the action of the helical spring and adapted to release the actuating sleeve for upward actuation by the helical spring upon rotation of the mandrel in an opposite direction, a retaining ring loosely disposed on the mandrel above the actuating sleeve and adapted to be moved upward by the actuating sleeve upon upward actuation thereof by the helical spring, and a plurality of slips carried by the retaining ring adapted to engage the well casing upon upward movement of the retaining ring 10 and adapted to become disengaged from the well casing when the retaining ring is released by the actuating sleeve upon downward movement of said actuating sleeve by said stud as the mandrel is rotated.

References Cited in the file of this patent UNITED STATES PATENTS 1,118,538 Driscoll Nov. 24, 1914 1,803,841 Crowell May 5, 1931 2,107,655 Vogt et al. Feb. 8, 1938 2,138,157 Halliburton Nov. 29, 1938 2,153,934 McKissick Apr. 11, 1939 2,604,945 Page July 29, 1952 

